INDIAN INSTITUTE OF TECHNOLOGY, KHARAGPUR
Date:
(FN/AN)
No. of Students: 163
Subject No: EV20001
2"d Year B. Tech.: AG, BT, MT
Time: 2 hrs.
Full Mark~: 60
Autumn Mid Semester Examination, 2012-2013
Subject Name: Environmental Science
Section 4
Answer all questions
l.
a)
Show that the gain for the climate system can be expressed as, GF
= ___!}___.
1- f
Where, G and fare the
transfer function and the feedback of the climate system respectively. Write down the above expression for several feedback mechanisms when linked in (i) series and (ii) parallel.
b)
Write the names of four gases. that exhibit greenhouse effect. What is climate and what do you mean by climatic variations?
c)
4+2+2=8
2+1+1=4
If the feedbacks from atmospheric water vapor, clouds, carbon dioxide and albedo are 0.1, 0.15,
0.3 and 0.15 then find the final gain for the climate system if the gain for zero feedback is 0.9.
3
2.
a)
Write down the different important sources of water pollution. How water pollution is related to
BOD? A sample of water contains Ca(HC0 3) 2 = 32.4 mg/1, Mg(HC0 3) 2 = 21.9 mg/1, MgCb =9.5 mg/1 and CaS04 = 6.8 mg/1. Find total hardness and permanent hardness?
b)
2+2+2=6
Draw a flow chart of sewage treatment and explain briefly. Explain the reverse osmosis process with diagram and explain how this process is used for desalination of brine.
3+6=9
3.
a)
Write the model equations for the main two components of the earth climate system. Show that earth emits long wave. If solar activity changes then how it will affects the earth climate? 7+3+2=12
b)
"The moist air is heavier than the dry air" - this statement is correct or wrong? why?
4.
Explain about the dispersal of air pollutants with different atmospheric stability conditions. Write
3
the names of plumes based on different environmental stability conditions. Also explain those plumes behavior with necessary diagram.
6+3+6=15